I would use the unofficial debian installer and install to the emmc from another computer. you need another *nix computer with git.
make sure the emmc switch is towards the hinge.
honestly other than you saying it was working before... a lot of this sounds like the emmc is either toggled off or not booting.
make sure the emmc switch is towards the hinge.
honestly other than you saying it was working before... a lot of this sounds like the emmc is either toggled off or not booting.